US4410974A - Capacitance detection type record stylus and method for making the stylus - Google Patents

Capacitance detection type record stylus and method for making the stylus Download PDF

Info

Publication number
US4410974A
US4410974A US06/300,451 US30045181A US4410974A US 4410974 A US4410974 A US 4410974A US 30045181 A US30045181 A US 30045181A US 4410974 A US4410974 A US 4410974A
Authority
US
United States
Prior art keywords
stylus
crystal plane
diamond
capacitance detection
detection type
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US06/300,451
Inventor
Keiji Segawa
Masaki Murakami
Keiichiro Doi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Victor Company of Japan Ltd
Original Assignee
Victor Company of Japan Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Victor Company of Japan Ltd filed Critical Victor Company of Japan Ltd
Assigned to VICTOR COMPANY OF JAPAN, LIMITED reassignment VICTOR COMPANY OF JAPAN, LIMITED ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: DOI, KEIICHIRO, MURAKAMI, MASAKI, SEGAWA, KEIJI
Application granted granted Critical
Publication of US4410974A publication Critical patent/US4410974A/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B9/00—Recording or reproducing using a method not covered by one of the main groups G11B3/00 - G11B7/00; Record carriers therefor
    • G11B9/06—Recording or reproducing using a method not covered by one of the main groups G11B3/00 - G11B7/00; Record carriers therefor using record carriers having variable electrical capacitance; Record carriers therefor
    • G11B9/07—Heads for reproducing capacitive information
    • G11B9/075—Heads for reproducing capacitive information using mechanical contact with record carrier, e.g. by stylus
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B19/00—Single-purpose machines or devices for particular grinding operations not covered by any other main group
    • B24B19/16—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding sharp-pointed workpieces, e.g. needles, pens, fish hooks, tweezers or record player styli
    • B24B19/165—Phonograph needles and the like
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/02—Elements
    • C30B29/04—Diamond
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B31/00—Diffusion or doping processes for single crystals or homogeneous polycrystalline material with defined structure; Apparatus therefor
    • C30B31/20—Doping by irradiation with electromagnetic waves or by particle radiation
    • C30B31/22—Doping by irradiation with electromagnetic waves or by particle radiation by ion-implantation

Definitions

  • the present invention relates to a capacitance detection type record stylus which detects signals stored in the form of minute pits along tracks on a recording medium as geometric variations, and a method for making such styluses.
  • the stylus comprises a diamond body provided with an electrode extending downwardly to a face that makes contact with the record surface.
  • the electrode needs to be bonded strongly to the underlying crystallographic structure of carbon atoms that constitute the diamond body so that the conductive atoms are not dislocated under the rigorous conditions.
  • the prior art attempts involve bombarding the diamond body with high velocity conductive particles such as hafnium or titanium, or using similar techniques, to permit conductive atoms to penetrate into the diamond to form the electrode.
  • high velocity conductive particles such as hafnium or titanium
  • satisfactory results have not been obtained due to the fact that the surface of the diamond on which the electrode is to be formed tends to present an obstacle to the introduction of particles and lattice defects occur in the bombarded crystal structure.
  • the present invention contemplates to use the crystal plane ⁇ 110 ⁇ as the electrode forming face of the diamond stylus body since the carbon atoms underlying the plane ⁇ 110 ⁇ are aligned to permit introduction of conductive atoms deep into the body. A greater amount of conductive atoms can thus be embedded into the crystal structure of the diamond to form an electrode having a strong bonding with the carbon atoms so that the electrode is rendered resistant to abrasion.
  • the present invention is characterized by the use of artificially made diamonds having flat faces which lie parallel to crystal planes ⁇ 111 ⁇ and ⁇ 100 ⁇ wherein any adjoining faces have the same crystal plane, either ⁇ 111 ⁇ or ⁇ 100 ⁇ .
  • a crystal plane ⁇ 110 ⁇ either flat, convex or concave, is formed between any two of the adjoining identical crystal planes by shaping the edge between them.
  • a conductive material is then deposited on the plane ⁇ 110 ⁇ by bombarding it with high velocity ions, for example, to form the stylus electrode.
  • FIG. 1 is a perspective view of a capacitance detection type stylus of the invention shown as resting over several tracks of a grooveless capacitance disk record;
  • FIG. 2 is a perspective view of an artificial diamond in which the crystal plane ⁇ 110 ⁇ is formed between adjoining crystal planes ⁇ 111 ⁇ ;
  • FIG. 3 is a side view of the diamond body of FIG. 2 showing the orientation of the crystal plane ⁇ 110 ⁇ relative to the adjacent planes ⁇ 111 ⁇ ;
  • FIG. 4 is a perspective view of the diamond when bombarded with high velocity ions to form a stylus electrode
  • FIG. 5 is a front view of the diamond body when the latter is cut into a stylus form after formation of an electrode on the crystal plane ⁇ 110 ⁇ ;
  • FIG. 6 is a perspective view of another example of the artificial diamond in which the crystal plane ⁇ 110 ⁇ is formed between adjoining crystal planes ⁇ 100 ⁇ .
  • FIG. 1 a capacitance detection type record stylus 10 for grooveless capacitance disks is shown as resting over several spiral or concentric tracks 11 of a disk record in which signals are stored as geometric variations in the form of minute pits.
  • the stylus 10 comprises a diamond body 12 provided with a narrow strip electrode 14 which extends downward to a contact face 16 having a width of several tracks. This electrode is formed on a crystal plane ⁇ 110 ⁇ of the diamond body.
  • the diamond body 12 is formed of an artificially made diamond, one example of which is shown in FIG. 2.
  • This artificial diamond is cut from an octahedral body, shown in broken lines, so that adjoining hexagon-shaped faces 21, 22, 23, 24 lie parallel to crystal plane ⁇ 111 ⁇ and rectangular-shaped faces 30 and 31 lie parallel to crystal plane ⁇ 100 ⁇ .
  • the artificial diamond of this type is available from General Electric as MPSD type diamonds and is found suitable for this invention since the crystal structure just described is in abundance in such artificial diamond.
  • the crystal plane ⁇ 110 ⁇ is formed between adjoining faces 20 and 21, for example, of the identical crystal structure by lapping the boundary line 40 between them in opposite directions normal to the line 40 as indicated by an arrow 41. This lapping leaves the diamond body with an elongate face as indicated by a broken-line rectangle 42 which lies in a direction parallel to the crystal plane ⁇ 110 ⁇ .
  • the adjoining faces 20 and 21 make an angle "a" of a known value.
  • the lapping is carried out so that the elongate face 42 makes substantially equal angles "b" to the adjoining ⁇ 111 ⁇ planes 20 and 21 and the lengthwise edges are parallel to the boundary line 40 and a width slightly larger than 0.8 micrometers.
  • the carbon atoms are aligned to permit conductive material or ions to penetrate unobstructed into a deeper region from the surface.
  • the ⁇ 110 ⁇ crystal plane 42 is bombarded with high velocity ions to form a conductive layer serving as the electrode 14 (see FIG. 4).
  • other techniques such as ion sputtering and vacuum deposition could also be employed for the electrode formation. Since the angle "a" is known in advance and the adjoining identical crystal planes are bounded by straight lines, the ⁇ 110 ⁇ crystal plane is formed in a short period of time with a high degree of precision by making use of the boundary line as a reference for the lapping operation.
  • the diamond body is shaped to remove hatched portions as shown in FIG. 5 into a suitable form having the contact face 16.
  • FIG. 6 Another example of the artificial diamond body is shown in FIG. 6.
  • This diamond has octagon-shaped crystal planes ⁇ 100 ⁇ adjoined by straight boundary lines and triangular-shaped crystal planes ⁇ 111 ⁇ bounded by the ⁇ 100 ⁇ planes.
  • the crystal plane ⁇ 110 ⁇ is also formed by lapping a boundary between any two of the ⁇ 100 ⁇ planes in a manner identical to that described above.

Abstract

A capacitance detection type record stylus comprises a body of artificial diamond having flat faces lying parallel to the crystal planes {111} and {100} wherein adjoining identical crystal planes are either {111} or {100}. A crystal plane {110} is formed between any two of the adjoining identical crystal planes by lapping the edge between them. A conductive material is deposited on the crystal plane {110} to form an electrode for detecting signals recorded as geometric variations on a recording medium. Because of the aligned carbon atoms beneath the crystal plane {110}, a substantial amount of the conductive material penetrates deeply into the diamond making the electrode resistant to wear.

Description

BACKGROUND OF THE INVENTION
The present invention relates to a capacitance detection type record stylus which detects signals stored in the form of minute pits along tracks on a recording medium as geometric variations, and a method for making such styluses.
Various attempts have hitherto been made to provide a capacitance detection type record stylus which is resistant to abrasion that occurs as a result of contact with the surface of a capacitance disk spinning at significantly high speeds. More specifically, the stylus comprises a diamond body provided with an electrode extending downwardly to a face that makes contact with the record surface. To ensure a high degree of resistance to wear the electrode needs to be bonded strongly to the underlying crystallographic structure of carbon atoms that constitute the diamond body so that the conductive atoms are not dislocated under the rigorous conditions.
The prior art attempts involve bombarding the diamond body with high velocity conductive particles such as hafnium or titanium, or using similar techniques, to permit conductive atoms to penetrate into the diamond to form the electrode. However, satisfactory results have not been obtained due to the fact that the surface of the diamond on which the electrode is to be formed tends to present an obstacle to the introduction of particles and lattice defects occur in the bombarded crystal structure.
SUMMARY OF THE INVENTION
The present invention contemplates to use the crystal plane {110} as the electrode forming face of the diamond stylus body since the carbon atoms underlying the plane {110} are aligned to permit introduction of conductive atoms deep into the body. A greater amount of conductive atoms can thus be embedded into the crystal structure of the diamond to form an electrode having a strong bonding with the carbon atoms so that the electrode is rendered resistant to abrasion.
One approach to making the diamond stylus body would involve the use of naturally available diamond stones and cutting them into a desired shape. However, there is no consistency in crystal structure between natural diamond stones and it is extremely rare that such stones present the {110} crystal plane. The cutting process would require an X-ray analysis to locate the desired crystal plane and is thus economically prohibitive for mass production.
The present invention is characterized by the use of artificially made diamonds having flat faces which lie parallel to crystal planes {111} and {100} wherein any adjoining faces have the same crystal plane, either {111} or {100}. A crystal plane {110}, either flat, convex or concave, is formed between any two of the adjoining identical crystal planes by shaping the edge between them. A conductive material is then deposited on the plane {110} by bombarding it with high velocity ions, for example, to form the stylus electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described in detail given by way of example with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of a capacitance detection type stylus of the invention shown as resting over several tracks of a grooveless capacitance disk record;
FIG. 2 is a perspective view of an artificial diamond in which the crystal plane {110} is formed between adjoining crystal planes {111};
FIG. 3 is a side view of the diamond body of FIG. 2 showing the orientation of the crystal plane {110} relative to the adjacent planes {111};
FIG. 4 is a perspective view of the diamond when bombarded with high velocity ions to form a stylus electrode;
FIG. 5 is a front view of the diamond body when the latter is cut into a stylus form after formation of an electrode on the crystal plane {110}; and
FIG. 6 is a perspective view of another example of the artificial diamond in which the crystal plane {110} is formed between adjoining crystal planes {100}.
DETAILED DESCRIPTION
In FIG. 1 a capacitance detection type record stylus 10 for grooveless capacitance disks is shown as resting over several spiral or concentric tracks 11 of a disk record in which signals are stored as geometric variations in the form of minute pits. The stylus 10 comprises a diamond body 12 provided with a narrow strip electrode 14 which extends downward to a contact face 16 having a width of several tracks. This electrode is formed on a crystal plane {110} of the diamond body.
According to the invention the diamond body 12 is formed of an artificially made diamond, one example of which is shown in FIG. 2. This artificial diamond is cut from an octahedral body, shown in broken lines, so that adjoining hexagon- shaped faces 21, 22, 23, 24 lie parallel to crystal plane {111} and rectangular- shaped faces 30 and 31 lie parallel to crystal plane {100}. The artificial diamond of this type is available from General Electric as MPSD type diamonds and is found suitable for this invention since the crystal structure just described is in abundance in such artificial diamond. The crystal plane {110} is formed between adjoining faces 20 and 21, for example, of the identical crystal structure by lapping the boundary line 40 between them in opposite directions normal to the line 40 as indicated by an arrow 41. This lapping leaves the diamond body with an elongate face as indicated by a broken-line rectangle 42 which lies in a direction parallel to the crystal plane {110}.
As clearly shown in FIG. 3, the adjoining faces 20 and 21 make an angle "a" of a known value. The lapping is carried out so that the elongate face 42 makes substantially equal angles "b" to the adjoining {111} planes 20 and 21 and the lengthwise edges are parallel to the boundary line 40 and a width slightly larger than 0.8 micrometers.
In the atomic structure underlying the {110} crystal plane, the carbon atoms are aligned to permit conductive material or ions to penetrate unobstructed into a deeper region from the surface. After the lapping process, the {110} crystal plane 42 is bombarded with high velocity ions to form a conductive layer serving as the electrode 14 (see FIG. 4). Obviously, other techniques such as ion sputtering and vacuum deposition could also be employed for the electrode formation. Since the angle "a" is known in advance and the adjoining identical crystal planes are bounded by straight lines, the {110} crystal plane is formed in a short period of time with a high degree of precision by making use of the boundary line as a reference for the lapping operation.
After the formation of the electrode 14, the diamond body is shaped to remove hatched portions as shown in FIG. 5 into a suitable form having the contact face 16.
Another example of the artificial diamond body is shown in FIG. 6. This diamond has octagon-shaped crystal planes {100} adjoined by straight boundary lines and triangular-shaped crystal planes {111} bounded by the {100} planes. The crystal plane {110} is also formed by lapping a boundary between any two of the {100} planes in a manner identical to that described above.

Claims (5)

What is claimed is:
1. A capacitance detection type record stylus for detecting signals recorded as geometric variations along a track on a recording medium, comprising:
a body of diamond having a crystal plane {110} formed between adjoining planes of an identical crystallographic structure; and
an electrode formed on said crystal plane {110} for detecting said signals.
2. A capacitance detection type record stylus as claimed in claim 1, wherein said diamond body is formed with a contact face which is adapted to make contact with said recording medium, said contact face having such a width that said stylus rests over several tracks of said recording medium, and wherein said electrode has a width substantially equal to the width of said track.
3. A capacitance detection type record stylus as claimed in claim 1, wherein said body comprises an artificially made diamond.
4. A capacitance detection type record stylus as claimed in claim 1, 2 or 3, wherein said crystal plane {110} is inclined at equal angles to said adjoining planes.
5. A capacitance detection type record stylus as claimed in claim 4, wherein said adjoining planes are parallel to crystal plane {111} or {100}.
US06/300,451 1980-09-09 1981-09-08 Capacitance detection type record stylus and method for making the stylus Expired - Fee Related US4410974A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP55-125134 1980-09-09
JP55125134A JPS6042532B2 (en) 1980-09-09 1980-09-09 Regeneration needle that detects changes in capacitance value

Publications (1)

Publication Number Publication Date
US4410974A true US4410974A (en) 1983-10-18

Family

ID=14902693

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/300,451 Expired - Fee Related US4410974A (en) 1980-09-09 1981-09-08 Capacitance detection type record stylus and method for making the stylus

Country Status (5)

Country Link
US (1) US4410974A (en)
JP (1) JPS6042532B2 (en)
CH (1) CH644222A5 (en)
DE (1) DE3135518A1 (en)
GB (1) GB2085639B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4535436A (en) * 1980-05-30 1985-08-13 Victor Company Of Japan, Limited Stylus having a graphite electrode

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3943276A (en) * 1974-06-03 1976-03-09 Zenith Radio Corporation Record tracking pickup structure for a capacitive disc

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3943276A (en) * 1974-06-03 1976-03-09 Zenith Radio Corporation Record tracking pickup structure for a capacitive disc

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4535436A (en) * 1980-05-30 1985-08-13 Victor Company Of Japan, Limited Stylus having a graphite electrode

Also Published As

Publication number Publication date
GB2085639B (en) 1984-09-05
CH644222A5 (en) 1984-07-13
JPS5750345A (en) 1982-03-24
DE3135518C2 (en) 1987-03-26
DE3135518A1 (en) 1982-04-08
JPS6042532B2 (en) 1985-09-24
GB2085639A (en) 1982-04-28

Similar Documents

Publication Publication Date Title
US4549238A (en) Magnetic head slider of ceramic material
US3826877A (en) Information playback system stylus
US3877705A (en) Diamond scanning element
CA1174176A (en) Keel-tipped stylus, and method and device for making keel-tipped stylus
US4410974A (en) Capacitance detection type record stylus and method for making the stylus
US4199782A (en) Stylus for reproducing capacitive videodisc
GB2104708A (en) Playback stylus and its manufacture
EP1003157B1 (en) Hard disk burnishing head
JPS5922250A (en) Scanning stylus of pickup
US3774918A (en) Phonograph pickup stylus
JPS5931763B2 (en) Cutting needle for disk recording media
US4480326A (en) Stylus having a conductive carbon layer
US4535436A (en) Stylus having a graphite electrode
US4357699A (en) Capacitance detection type stylus with diamond body and electrode having the same wear resistance properties
GB2140190A (en) Stylus for capacity change detection type disc system
US4497052A (en) Stylus for reproducing information signals recorded on a recording medium
US4503529A (en) Record stylus for capacitance disks
US4388714A (en) Technique for uniform stylus configuration
JPS61123001A (en) Reproducing stylus for tracing sound groove
US4330915A (en) Technique for uniform stylus configuration
JPS58143449A (en) Manufacture of reproducing stylus for video disk and forming tool for form fine groove formation
US4498163A (en) Diamond pickup stylus with good grindability
JPS63140401A (en) Record stylus
JPS58177543A (en) Reproducing stylus for video disk and its manufacture
JPS5845097B2 (en) Capacitive video disc playback needle

Legal Events

Date Code Title Description
AS Assignment

Owner name: VICTOR COMPANY OF JAPAN, LIMITED, 3-12, MORIYA-CHO

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:SEGAWA, KEIJI;MURAKAMI, MASAKI;DOI, KEIICHIRO;REEL/FRAME:003918/0097

Effective date: 19810821

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, PL 96-517 (ORIGINAL EVENT CODE: M170); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 4

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FEPP Fee payment procedure

Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

LAPS Lapse for failure to pay maintenance fees
FP Lapsed due to failure to pay maintenance fee

Effective date: 19911020

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362